What supplements should I take? It’s not an easy question to answer. While we all want to make sure we are protecting our (and our family’s) health by working toward achieving ideal nutrition, we also don’t want to spend hundreds of dollars and pop dozens of pills. The fact is that if you regularly eat high-quality whole foods, your gastrointestinal tract functions well, and you’re usually healthy, then you probably don’t need many dietary supplements.
However, some nutrients are vital or highly beneficial and our diets simply may not be providing enough of them. Even if we strive to live a healthy lifestyle, many of us fall outside the area of “ideal” health and nutrition. Sometimes we lack the time, money or inclination to prepare perfectly wholesome meals every day. With age and illness, intestines may not efficiently absorb nutrients, and acute and chronic diseases increase demands for certain nutrients. To be sure, supplement needs vary by individual, but these five are the most often-recommended dietary supplements. If you have questions, always check with your doctor.
Bones, nerves, muscles, hormones and enzymes need calcium. Blood levels are maintained at a fairly even keel and if they drop, calcium is removed from bone. It’s crucial that we don’t run a long-term deficit.
Dosage: The recommended dietary allowance (RDA) for adults is 1,000 mg a day. The intake increases to 1,200 mg a day for women older than 50 and men older than 70.
Other sources: If we eat well, we should be able to satisfy the requirements from food. Most experts say the best way to get calcium is from cruciferous vegetables (especially dark-green leafy vegetables), dairy products, sardines, peanuts, sesame seeds, sunflower seeds, dried beans, figs and seaweed.
Deficiency: Many people, particularly those older than 70, fall short of recommended calcium intake without supplements. For instance, women 50 to 70 typically get about 780 mg of calcium from food. Long-term deficiency increases risk for osteoporosis.
Pros & cons: For decades, doctors routinely recommended calcium supplements. The side effects seemed relatively minor—mainly constipation and bloating. On the other hand, the risk of a devastating, osteoporosis-related bone fracture declined 12 percent with calcium plus vitamin D supplementation.
Then, in 2010, two reports linked calcium supplementation with a 24 to 31 percent increased risk of heart attacks. Other research has not shown cardiovascular risks.
Always try to obtain your calcium from food, says Douglas C. Bauer, a doctor and professor of medicine, epidemiology and biostatistics at the University of California, San Francisco. For those unable to do so, Bauer recommends one of two types of calcium supplements: calcium carbonate and calcium citrate.
Less-expensive calcium carbonate contains a higher percentage of calcium (40 percent), but it’s more likely to cause constipation and bloating. Adequate absorption requires stomach acid, which declines with age. If you’re older than 60 or take an antacid, use calcium citrate. A typical calcium citrate dosage is one 1,000-mg tablet, two to three times a day, or 420 to 630 mg of calcium. Don’t exceed 2,500 mg of calcium in food and supplements a day.
Like calcium, magnesium is a major mineral in the body that contributes to bone structure. It’s also required for many chemical reactions; nerve and muscle function; protein synthesis; energy production; blood pressure and heart rate regulation; and blood sugar control.
Dosage: The RDA varies depending on age and gender. For men 19 to 30, the RDA is 400 mg, thereafter rising to 420 mg. The RDA for women 19 to 30 is 310 mg; 320 mg for those nursing a baby or older than 31; and 360 mg during pregnancy.
Other sources: Particularly good food sources are green leafy vegetables, legumes, whole grains, avocados, seeds and nuts.
Deficiency: National health surveys show that nearly half of kids and adults fail to consume adequate amounts of dietary magnesium: Among teens 14 to 18, and adults older than 70, more than two-thirds don’t get enough magnesium.
People at higher risk for magnesium deficiency include those with kidney disease, intestinal disorders (for example, celiac disease and Crohn’s disease), type 2 diabetes, alcohol dependence, and the elderly. Used long-term, some diuretics and proton pump inhibitors (drugs such as Nexium and Prevacid) can cause magnesium deficiency. Most people—unless extremely malnourished or ill—don’t develop signs of severe magnesium deficiency. Early signs include reduced appetite, nausea, vomiting, fatigue and weakness. Suboptimal magnesium intake can, over time, increase risk of high blood pressure, cardiovascular disease, stroke, type 2 diabetes, osteoporosis and migraines.
Pros & cons: When you shop for supplements, you’ll see that magnesium is always bound to another chemical. Magnesium bound to aspartate, citrate, lactate and chloride forms is better absorbed and more bioavailable than magnesium oxide and magnesium sulfate. Magnesium supplements can correct low blood levels of magnesium (a condition detected by a blood test). Studies show that higher intakes of magnesium from food and supplements combined reduced the risk of developing type 2 diabetes. Although results are mixed, some studies show that magnesium supplements improve insulin sensitivity in people who already have type 2 diabetes. Supplements also show promise for people with migraines, premenstrual syndrome (PMS), high cholesterol and coronary artery disease.
Your dosage should depend upon how much you’re getting from food, your age, sex, the condition you’re trying to treat, and whether or not you’re deficient. As always, it’s better not to exceed the RDA. While the kidneys do a good job of eliminating excess, high intake from supplements can trigger diarrhea, intestinal cramping and nausea. (Some commercial laxatives are magnesium-based.) The good news is that if you take calcium supplements, magnesium counteracts their constipating effect.
3. Vitamin D
Vitamin D promotes calcium absorption from the intestines. Its multiple functions include bone mineralization, cell growth and reduction of inflammation. It’s also involved in the function of nerves, muscles and the immune system.
Dosage: RDA is 400 IU for infants younger than a year, 600 IU for children and adults, and 800 IU for people older than 70.
Other sources: In the presence of the sun’s UVB rays, our skin manufactures vitamin D. A few facts to keep in mind: Sunscreen can interfere with the process; darker-skinned people require more UVB exposure to generate vitamin D; vitamin D production becomes less efficient as we age; and winter sunlight in much of the northern U.S. is too weak to stimulate the process.
Only a few foods contain much vitamin D: oily fish, eggs (from vitamin D-fed hens), sun-exposed mushrooms, and fortified products including dairy, soy milk, orange juice and cereals.
Deficiency: About 1 billion people worldwide have vitamin D deficiency (blood levels less than 20 ng/mL) or insufficiency (21 to 29 ng/mL), says Michael F. Holick, a doctor, researcher and professor of medicine at Boston University School of Medicine. Vitamin D deficiency causes skeletal deformities in children, and osteomalacia (a painful softening of the bones) and osteoporosis in adults. Deficiency can lead to falls and bone fractures, and has been linked to a higher risk of cardiovascular disease; some cancers; respiratory infections; asthma; and autoimmune disorders such as multiple sclerosis, depression, diabetes, reduced fertility and Alzheimer’s-type dementia.
Groups at risk for insufficiency include breast-fed infants; older adults; people who are obese; people with scant exposure to the sun; people with liver or kidney disease; and those with intestinal diseases or surgeries that limit fat absorption. Pregnant women require adequate vitamin D to ensure normal fetal bone development.
Pros & cons: Because we don’t get much vitamin D from food (about 200 IU a day), many health authorities recommend supplements, starting in infancy. The Endocrine Society, an international organization dedicated to research and education about hormones, recommends daily supplementation as follows to prevent deficiency:
Infants 0 to 12 months: 400 to 1,000 IU; don’t exceed 2,000 IU
Children and adolescents between 1 and 18: 600 to 1,000 IU; don’t exceed 4,000 IU
Adults older than 18: 1,500 to 2,000 IU; don’t exceed 10,000 IU
If you’re in one of the groups at risk for deficiency, ask your doctor for a blood test for 25-hydroxyvitamin D to better determine your optimal supplement dose. Excessive vitamin D can elevate blood levels of calcium, leading to damage to kidneys, heart and blood vessels. Sun exposure does not lead to vitamin D overdose.
4. Fish Oil
Fatty fish are rich in the omega-3 fatty acids docosapentaenoic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—critical to fetal development and health throughout life, says Robert C. Block, a doctor at the University of Rochester School of Medicine and Dentistry in Rochester, New York. They become incorporated into many parts of the body (notably cell membranes), and have anti-inflammatory effects (read more about inflammation in 9 Foods that Reduce Inflammation).
Dosage: Many health experts recommend consuming fatty fish once or twice a week, or taking supplements. The government doesn’t set RDAs for fatty acids, but typical fish oil doses in studies range from 1 to 4 grams a day. Because of the importance of EPA and DHA during fetal and infant development, adequate intake is particularly important for pregnant and nursing women.
Other sources: Fish is the best dietary source for preformed EPA and DHA. However, algal sources are becoming increasingly available.
Deficiency: Fatty acids come in two main varieties: omega-3 and omega-6. Modern diets often contain too little of the former and too much of the latter. Signs of essential fatty acid deficiency include poor growth and development in infants and children, dry scaly rash, increased susceptibility to infection and poor wound healing. Low levels of EPA and DHA are associated with inflammatory conditions, cardiovascular disease, reduced cognitive function and some psychological disorders (attention deficit hyperactivity disorder, depression and bipolar disorder).
Pros & cons: Getting adequate fatty acids is crucial. Eating fatty fish seems to reduce the risk of developing heart disease. (However, recent studies show fish oil supplementation offers no reduction in death, heart attack or stroke in people at risk for cardiovascular disease.) In people who already have heart disease, supplements reduce deaths, but don’t seem to protect against so-called “cardiovascular events” (heart attacks and strokes).
Fatty acid intake affects inflammation levels and brain health. Preliminary research suggests fish and fish oil supplements decrease breast cancer risk. The brain depends upon adequate amounts of omega-3 fatty acids, especially DHA. Diets high in these oils protect against age-related cognitive decline and Alzheimer’s disease. Preliminary evidence of benefits also exist (as adjuncts to conventional treatment) of dietary fish and fish oil supplements in attention deficit hyperactivity disorder, asthma and age-related macular degeneration. In terms of side effects, fish oil supplements may cause fishy-tasting burps, heartburn and nausea, but no major health risks.
Probiotics are live microorganisms (bacteria and yeast) similar to those already residing in our intestinal tract. Our normal “gut flora” benefit us by outcompeting disease-causing microbes, enhancing immune function, maintaining mucous membrane health, optimizing digestion and manufacturing vitamins.
Dosage: There is no RDA; dosage is based on the number of colony forming units (CFUs) per capsule and range from 1 to 10 billion CFUs daily, divided.
Other sources: Fermented foods (yogurt, kefir, cultured buttermilk, unpasteurized sauerkraut, kimchi, miso, natto, tempeh) naturally contain beneficial microbes.
Deficiency: While it’s impossible to be “deficient” in probiotics, it’s common to have an ecologic disturbance in gut flora. Scientists link imbalances to diarrhea, asthma, irritable bowel syndrome, type 1 and 2 diabetes, obesity and possibly cardiovascular disease.
Pros & cons: Preliminary research usually focuses on specific strains of bacteria (Lactobacillus or Bifidobacteria) and yeast (Saccharomyces boulardii). Positive studies exist for viral diarrhea in children (specifically rotovirus); diarrhea associated with antibiotics and chemotherapy; diarrhea caused by Clostridium difficile; traveler’s diarrhea; eczema; bacterial vaginosis; infantile colic; and inflammatory bowel disease and irritable bowel syndrome. Prophylactic use may reduce the severity and frequency of respiratory infections. Probiotics appear to be safe when taken within dosage guidelines. If you have a colicky baby and want to try probiotics, talk to your pediatrician.
Linda B. White, M.D. works as a lecturer and freelance writer. Her most recent books are Health Now: An Integrative Approach to Personal Health and 500 Time-Tested Home Remedies and the Science Behind Them, coauthored with Barbara Seeber and Barbara Brownell Grogan.